What is an Kenya evisa?

An evisa is an electronic visa that allow foreign nationals to enter Kenya. There are two different types of evisas: The Single-Entry evisa is for those intending to stay in Kenya for an extended period, for the purpose of either tourism, business or medical treatment. The evisa is valid for 90 days, and can be extended for an additional 90 days.
The Transit evisa is for those connecting through Kenya. The evisa is valid for a period of 72 hours. Those with a direct flight (i.e., those who does not intend to leave the airport) do not require a Transit evisa.

Which foreign nationals are eligible for an evisa?
Albania, Algeria, Andorra, Angola, Antigua and Bermuda, Argentina, Australia, Austria, Bahrain, Bangladesh, Belarus, Belgium, Benin, Bhutan, Bolivia, Bosnia and Herzegovina, Brazil, Bulgaria, Burkina Faso, Cambodia, Canada, Cape Verde, Central African Rep, Chad, Chile, China, Colombia, Comoros, Congo (Brazzaville), Congo (Democratic Rep), Costa Rica, Croatia, Cuba, Czech Republic, Denmark, Djibouti, Dominican Republic, East Timor, Ecuador, Egypt, El Salvador, Equatorial Guinea, Estonia, Finland, France, Gabon, Georgia, Germany, Greece, Greenland, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, Hong Kong (SAR), Hungary, Iceland, India, Indonesia, Iran, Ireland (Republic), Israel, Italy, Ivory Coast, Japan, Jordan, Kampuchea, Kazakhstan, Kirghizistan, Korea South, Kuwait, Laos, Latvia, Liberia, Liechtenstein, Lithuania, Luxembourg, Macedonia, Macau (SAR), Madagascar, Malagasy, Malta, Marshall Islands, Mauritania, Mexico, Micronesia, Moldova, Monaco, Mongolia, Montenegro, Morocco, Mozambique, Myanmar (Burma), Nepal, Netherlands, New Zealand, Nicaragua, Niger, Nigeria, Norway, Oman, Pacific Isles, Pakistan, Palau, Panama, Paraguay, Peru, Philippines, Poland, Portugal, Qatar, Reunion, Romania, Russian Federation, Salvador, Saint Christopher Cape, Sao Tome & Principe, Saudi Arabia, Serbia, Slovakia, Slovenia, South Sudan, Spain, Sri Lanka, Sudan, Suriname, Sweden, Switzerland, Taiwan, Thailand, Togo, Tunisia, Turkey, Turkmenistan, Ukraine, United Arab Emirates, United Kingdom, United States, Uruguay, Uzbekistan, Vatican City, Venezuela, Vietnam, Yugoslavia and former States of Yugoslavia.